Vacuum heat treatment method for different materials of piston rod

---

The piston rod is the connecting part that supports the work of the piston. Most of them are used in the oil cylinder and the cylinder motion execution part. It is a moving part with frequent movements and high technical requirements.

Taking the hydraulic cylinder as an example, it is composed of: cylinder barrel, piston rod (cylinder rod), piston, and end cover. The quality of its processing directly affects the life and reliability of the entire product. The piston rod has high processing requirements, and its surface roughness is required to be Ra0.4 ~ 0.8μm, and the requirements for coaxiality and wear resistance are strict. The main materials of the piston rod are: 40Cr, No. 45 steel, 2Cr13, these materials need to undergo some processing to be well used in these machinery industries, and only after special processing can our piston rods be used in these machinery industries. stand out.

Therefore, the processing procedure used is vacuum heat treatment. Only the piston rod that has undergone vacuum heat treatment can obtain sufficient strength and surface hardness, as well as the ability of corrosion resistance, friction resistance, fatigue resistance and seizure resistance.

1.No. 45 steel:

Vacuum heat treatment process: preliminary vacuum heat treatment – vacuum low temperature spheroidizing annealing – vacuum quenching – vacuum critical temperature quenching – vacuum high frequency quenching.

No. 45 steel is a medium carbon steel 45 steel piston rod for vacuum heat treatment, mainly to change the internal structure and performance of the steel through heating, heat preservation and cooling of the steel in the solid state. After vacuum quenching, the surface hardness can reach 45-52HRC, which can obtain comprehensive mechanical properties such as high strength and toughness.

2.2Cr13:

Vacuum heat treatment process: preliminary vacuum heat treatment process – quenching and tempering treatment – stress relief treatment – vacuum high frequency quenching, vacuum low temperature tempering

2Cr13 steel has good machinability, so it can have excellent corrosion resistance and good toughness after heat treatment. In order to maximize 2Cr13, the heating temperature, time, holding time, and cooling method must be correctly determined, so that the surface of the vacuum heat treated 2Cr13 piston rod can have high hardness and high wear resistance through the correct vacuum heat treatment process. In addition, high resistance to pitting corrosion, high fatigue strength, and high strength and toughness, so as to meet the quality requirements of the piston rod.

3.40Cr:

Vacuum heat treatment process: preparatory vacuum heat treatment – eliminating internal stress of workpiece – vacuum quenching and vacuum tempering operation – workpiece quality inspection

40Cr steel is a kind of low hardenability quenched and tempered steel, which has the characteristics of high strength, good plasticity, strong toughness and good mechanical properties. Moreover, it can improve the plasticity and toughness of the steel through proper tempering, so that the strength, hardness, toughness and plasticity are properly matched to meet the performance requirements of the piston rod.

Equipment selection: The RVGQ series vacuum air quenching furnace produced by SIMUWU is a high-quality product for the vacuum heat treatment of tools and molds. The good temperature control accuracy and temperature control uniformity ensure the effective progress of the vacuum air quenching process. SIMUWU specializes in the manufacture of vacuum furnaces, has more than ten years of relevant experience, and has a good reputation in the field of vacuum furnace manufacturing. The product line includes vacuum annealing furnace, vacuum oil quenching furnace, vacuum brazing furnace, etc., which are widely sold in developed and developing countries.